Hello @Nethra Viswanathan ,
welcome to this moderated Azure community forum.
You probably already found the documentation of Azure Digital Twins, including a quickstart.
Check out this series of blog posts showing a practical demonstration of how to use Azure Digital Twins.
Also check out this video about using Digital Twins.
Regarding the API values, Azure Digital Twins is agnostic where the data is coming from.
As you will see, either Logic Apps or Azure Functions are used to ingest twin data into Digital Twin instances. These message could be coming from an IoT Hub, ingesting them using some API could work too.
This will provide you enough pointers to get started yourself.
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